The organic transistor employing an organic semiconductor can be formed on a plastic substrate and enables enlargement of a screen, which cannot readily be achieved by a silicon transistor. In particular, the organic transistor employing a soluble organic semiconductor can be produced at a lower cost without employing a vacuum process, and is promising for application to new devices such as flexible electronic paper sheets and information tags.
A π-conjugated compound and a device employing the π-conjugated compound are disclosed in Japanese Patent Application Laid-Open Nos. 2003-221434, 2003-261655, 2003-268083, and 2003-292588.